Graceful: Cancel Process on monitor pages & HammerTime (#9213)

* Graceful: Create callbacks to with contexts

* Graceful: Say when Gitea is completely finished

* Graceful: Git and Process within HammerTime

Force all git commands to terminate at HammerTime
Force all process commands to terminate at HammerTime
Move almost all git processes to run as git Commands

* Graceful: Always Hammer after Shutdown

* ProcessManager: Add cancel functionality

* Fix tests

* Make sure that process.Manager.Kill() cancels

* Make threadsafe access to Processes and remove own unused Kill

* Remove cmd from the process manager as it is no longer used

* the default context is the correct context

* get rid of double till

1 files changed, 11 insertions, 3 deletions

diff --git a/modules/git/blame.go b/modules/git/blame.go
index 4f4343fe96..5a9ae9a74f 100644
--- a/modules/git/blame.go
+++ b/modules/git/blame.go
@@ -6,6 +6,7 @@ package git
 
 import (
 	"bufio"
+	"context"
 	"fmt"
 	"io"
 	"os"
@@ -28,6 +29,7 @@ type BlameReader struct {
 	output  io.ReadCloser
 	scanner *bufio.Scanner
 	lastSha *string
+	cancel  context.CancelFunc
 }
 
 var shaLineRegex = regexp.MustCompile("^([a-z0-9]{40})")
@@ -76,7 +78,8 @@ func (r *BlameReader) NextPart() (*BlamePart, error) {
 
 // Close BlameReader - don't run NextPart after invoking that
 func (r *BlameReader) Close() error {
-	process.GetManager().Remove(r.pid)
+	defer process.GetManager().Remove(r.pid)
+	defer r.cancel()
 
 	if err := r.cmd.Wait(); err != nil {
 		return fmt.Errorf("Wait: %v", err)
@@ -97,20 +100,24 @@ func CreateBlameReader(repoPath, commitID, file string) (*BlameReader, error) {
 }
 
 func createBlameReader(dir string, command ...string) (*BlameReader, error) {
-	cmd := exec.Command(command[0], command[1:]...)
+	// FIXME: graceful: This should have a timeout
+	ctx, cancel := context.WithCancel(DefaultContext)
+	cmd := exec.CommandContext(ctx, command[0], command[1:]...)
 	cmd.Dir = dir
 	cmd.Stderr = os.Stderr
 
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
+		defer cancel()
 		return nil, fmt.Errorf("StdoutPipe: %v", err)
 	}
 
 	if err = cmd.Start(); err != nil {
+		defer cancel()
 		return nil, fmt.Errorf("Start: %v", err)
 	}
 
-	pid := process.GetManager().Add(fmt.Sprintf("GetBlame [repo_path: %s]", dir), cmd)
+	pid := process.GetManager().Add(fmt.Sprintf("GetBlame [repo_path: %s]", dir), cancel)
 
 	scanner := bufio.NewScanner(stdout)
 
@@ -120,5 +127,6 @@ func createBlameReader(dir string, command ...string) (*BlameReader, error) {
 		stdout,
 		scanner,
 		nil,
+		cancel,
 	}, nil
 }